340 Stock Rockers with larger springs

[DeerTrailDude]

Hi the guys at FBBO say this is the place to get small block info. Even though I'm restoring a '73 Road Runner it's a 340 car. Thirty plus years ago I built plenty of big blocks but this is my first small block.
This has probably been discussed before but I'm looking for some expert info. About a year ago I sent my heads to a machine shop simply wanting a good valve job. They said they could increase the valve size and replace the springs for about the same cost. Now that I'm finally assembling the engine (I've slowed down at the age of 70) I discovered the retainers are larger than 340 stock springs. Like many others around Colorado that machine shop has gone out of business so I can't get any info on parts they used. I've seen that a 340 retainer is 1.340". The retainers now are 1.435". Will I have any problem running these with the stock 340 rocker arms? I see the rocker arms seem to be "clearanced" that I have read is normal for 340 units. I'm attaching pics to help explain.
Thanks, just an old big block guy asking dumb small block questions!

 

[Newbomb Turk]

I can’t tell from the picture if it’s hitting or not.

If it’s not hitting send it. If it’s hitting see if you can find a .050 down set of locks.

You’d need to measure your installed height and if the .050 down locks put you over the top for seat pressure you can remove a shim.

Thats assuming you have a shim or shims under the spring.

 

[junkyardhero]

dykem and run them 'round the horn and see if anybody is getting to know each other.

if there's room for the holy ghost then ship it.

 

[teringer]

I changed to bee hive springs with smaller retainers ,no problem now

 

[DeerTrailDude]

Looks to my old eyeballs that there is a tiny amount of clearance. No shims under the springs. Just wondering if anyone knows the maximum retainer diameter the stock 340 rockers will be good with.

 

[Dart Frog]

I just went out and measured my x-heads they are assembled with 1.43 chromoly retainers. I always ran them with stock 340 rocker arms with no clearance issues. I think you're good.

 

[ch1ll]

Beehive springs are the way to go. It's a huge performance upgrade as well.

 

[Bewy]

Three for beehives. Every time you 'clearance' something you weaken it.

 

[TT5.9mag]

It's a huge performance upgrade as well.

That is not necessarily true.

 

[RustyRatRod]

Beehive springs are the way to go. It's a huge performance upgrade as well.

Say what? Uhhh.....no.

 

[RustyRatRod]

Behive springs are ok, but in this case they are good for masking the underlying issue. Incorrectly located rocker shafts. This is true of 99.9% of all Mopar factory shaft mounted rocker systems. If you really want it RIGHT, get with Mike at @B3RE. He is a class act and will help you figure out what you need.

 

[DeerTrailDude]

I just went out and measured my x-heads they are assembled with 1.43 chromoly retainers. I always ran them with stock 340 rocker arms with no clearance issues. I think you're good.

Thanks, that's what I was looking for! I hear the stock 340 rockers are beefier than other rockers and have a clearance area built in them from the factory.

I just went out and measured my x-heads they are assembled with 1.43 chromoly retainers. I always ran them with stock 340 rocker arms with no clearance issues. I think you're good.

 

[Newbomb Turk]

Behive springs are ok, but in this case they are good for masking the underlying issue. Incorrectly located rocker shafts. This is true of 99.9% of all Mopar factory shaft mounted rocker systems. If you really want it RIGHT, get with Mike at @B3RE. He is a class act and will help you figure out what you need.

It probably won’t happen. Beehives are cheaper. It’s not about fixing an issue, it’s about getting it done as cheap as possible.

I’ve NEVER seen a beehive that was an upgrade. Ever. I don’t use them and will never again unless I see some real reason to use them.

The “beehive” spring isn’t new. It’s not even close to new. But, many guys have never heard of them until 10 or 15 years ago so they thinks it’s new.

And we all know new is better…

 

[ch1ll]

Behive springs are ok, but in this case they are good for masking the underlying issue. Incorrectly located rocker shafts. This is true of 99.9% of all Mopar factory shaft mounted rocker systems. If you really want it RIGHT, get with Mike at @B3RE. He is a class act and will help you figure out what you need.

While I agree with you here,

Say what? Uhhh.....no.

I do not agree here.

 

[RustyRatRod]

While I agree with you here,

I do not agree here.

It's ok. Cause we're adults.

 

[junkyardhero]

It's ok. Cause we're adults.

this is an entirely reasonable reply and frankly i shall not stand for it.

i require vehement opposition and personal affront to be voiced and insults hurled.

 

[Newbomb Turk]

this is an entirely reasonable reply and frankly i shall not stand for it.

i require vehement opposition and personal affront to be voiced and insults hurled.

I AGREE. Slap his retirement aged behind around a bit and get him back in line.

You can’t take him anywhere. It’s embarrassing.

 

[ch1ll]

I AGREE. Slap his retirement aged behind around a bit and get him back in line.

You can’t take him anywhere. It’s embarrassing.

I probably should be second in line for a slapping.

 

[Newbomb Turk]

I probably should be second in line for a slapping.

We could use a good slapping every now and then. RRR just needs it more often. WAY more often.

 

[fishmens67]

This is true of 99.9% of all Mopar factory shaft mounted rocker systems. If you really want it RIGHT, get with Mike at @B3RE.

Who in their right mind would spend the money on geometry correction using factor paddle rockers.
Waste of money for sure, even if it's possible to correct geometry with a paddle rocker, which I highly doubt.

 

[Desoto291hemi]

Don’t worry,,,,stock rockers will usually clear 1.500 retainers,,,,but,,,always check to verify .
Tolerance stack up can occur,,,,always check to be sure .

Tommy

 

[pomonamissel]

did a 340 with adjustable iron rockers and sbchevy springs once , had to clearance the underside from hitting and rubbing through the lift of the cam . engine builder never saw an issue until it squired oil from the rocker shaft on # one and it wet the battery with a stream of oil every time it went through the cam lift .

 

[pomonamissel]

oh ya nothing looked wrong

 

[Uncle Bob]

Get a short piece of .030 welding wire and check between the retainer and the rocker. That advice came from the rocker arm geometry guy when I was grinding on my 273 adjustables to fit on Edelbrock heads with large diameter valve springs

 

[Newbomb Turk]

Who in their right mind would spend the money on geometry correction using factor paddle rockers.
Waste of money for sure, even if it's possible to correct geometry with a paddle rocker, which I highly doubt.

If the heads were rebuilt it’s possible the rebuilder didn’t give a crap about stem height and set them long.

That changes geometry.

Like I said, if they aren’t hitting send it. My rule is IF you have to grind on a rocker, fix it without a grinder.